commit a02943f3b11e5915e1eca651c01e60ebd7afd8a6
author Vishnu Nair <vishnun@google.com> Sat Jun 03 13:44:46 2023 -0700
committer Vishnu Nair <vishnun@google.com> Fri Jun 23 20:16:33 2023 +0000
tree 47ff5733f1b4575d53ab512e7d038da77461341c
parent e371d683a1f39c34c3339d323937e4810d24d2d4

[sf] optimize snapshot updates

Modify the snapshot update logic so its easier to maintain. Instead of
walking the tree and updating all the snapshots, this cl introduces a
preliminary step of walking though all the requested changes and
updating the affected snapshots by merging the changes to the snapshot.
This is followed by walking down the tree and updating properties that
are dependent on the parent snapshots.

If the changes are confined to buffer updates, then the fast path avoids
walking down the tree.

Bug: 238781169
Test: presubmit

Change-Id: Ic9aa66c376bf7ea80e38b321dd08b8d0f69559a9

services/surfaceflinger/FrontEnd/LayerLifecycleManager.cpp

diff --git a/services/surfaceflinger/FrontEnd/LayerLifecycleManager.cpp b/services/surfaceflinger/FrontEnd/LayerLifecycleManager.cpp
index c9eb9c4..1712137 100644
--- a/services/surfaceflinger/FrontEnd/LayerLifecycleManager.cpp
+++ b/services/surfaceflinger/FrontEnd/LayerLifecycleManager.cpp
@@ -17,7 +17,7 @@
 #define ATRACE_TAG ATRACE_TAG_GRAPHICS
 
 #undef LOG_TAG
-#define LOG_TAG "LayerLifecycleManager"
+#define LOG_TAG "SurfaceFlinger"
 
 #include "LayerLifecycleManager.h"
 #include "Client.h" // temporarily needed for LayerCreationArgs
@@ -51,6 +51,7 @@
                              it->second.owner.getDebugString().c_str());
         }
         mAddedLayers.push_back(newLayer.get());
+        mChangedLayers.push_back(newLayer.get());
         layer.parentId = linkLayer(layer.parentId, layer.id);
         layer.relativeParentId = linkLayer(layer.relativeParentId, layer.id);
         if (layer.layerStackToMirror != ui::INVALID_LAYER_STACK) {
@@ -202,6 +203,10 @@
                 continue;
             }
 
+            if (layer->changes.get() == 0) {
+                mChangedLayers.push_back(layer);
+            }
+
             if (transaction.flags & ISurfaceComposer::eAnimation) {
                 layer->changes |= RequestedLayerState::Changes::Animation;
             }
@@ -244,6 +249,7 @@
                     bgColorLayer->what |= layer_state_t::eColorChanged |
                             layer_state_t::eDataspaceChanged | layer_state_t::eAlphaChanged;
                     bgColorLayer->changes |= RequestedLayerState::Changes::Content;
+                    mChangedLayers.push_back(bgColorLayer);
                     mGlobalChanges |= RequestedLayerState::Changes::Content;
                 }
             }
@@ -290,6 +296,7 @@
         }
     }
     mDestroyedLayers.clear();
+    mChangedLayers.clear();
     mGlobalChanges.clear();
 }
 
@@ -310,10 +317,25 @@
     return mDestroyedLayers;
 }
 
+const std::vector<RequestedLayerState*>& LayerLifecycleManager::getChangedLayers() const {
+    return mChangedLayers;
+}
+
 const ftl::Flags<RequestedLayerState::Changes> LayerLifecycleManager::getGlobalChanges() const {
     return mGlobalChanges;
 }
 
+const RequestedLayerState* LayerLifecycleManager::getLayerFromId(uint32_t id) const {
+    if (id == UNASSIGNED_LAYER_ID) {
+        return nullptr;
+    }
+    auto it = mIdToLayer.find(id);
+    if (it == mIdToLayer.end()) {
+        return nullptr;
+    }
+    return &it->second.owner;
+}
+
 RequestedLayerState* LayerLifecycleManager::getLayerFromId(uint32_t id) {
     if (id == UNASSIGNED_LAYER_ID) {
         return nullptr;